KR20040023684A - Blood dialyzer - Google Patents

Abstract

A hemodialysis apparatus that carries out hemodialysis treatment by measuring or calculating the blood volume or its volume change as a blood indication level, and by controlling dialysis conditions according to said target blood indication level, wherein the chronological course of said blood indication level is defined as a target control line, and the primary blood volume (BV0) can be calculated as blood indication level. In the former part of the dialysis operation, the water removal is controlled so that the circulating blood volume in the body approach to the standard blood volume (BV st) with the use of said target control line. After the water removal of the former part of the dialysis operation, when the circulating blood volume in the body attains the standard blood volume (BV st), the latter part of the dialysis operation is started. In said latter part of the dialysis operation, the water removal operation is performed by substantively maintaining said standard blood volume (BV st). <IMAGE>

Description

Hemodialysis Device {BLOOD DIALYZER}

For the treatment of patients with impaired renal function, conventionally, the treatment for purifying blood by dialysis and filtration through a semipermeable membrane has been performed. In this device, it is important to keep the patient's circulating blood volume appropriately in order to perform safe and effective blood purification. Sudden or excessive water removal may cause blood pressure drop, shock, etc. by excessively reducing the circulating blood volume of the patient. On the contrary, if the water removal is slow, blood purification takes a long time, and if there is not enough distillation, hypertension or heart failure may occur. Therefore, a hemodialysis apparatus for performing dehydration while monitoring the blood state of a patient has been developed. For example, Japanese Patent Application Laid-open No. Hei 6-83723 describes an estimator for estimating a body fluid state by a hematocrit meter, and a control device for controlling a blood pump or an ultra-pressure based on the output of the estimator. This device is convenient because dividing is directly controlled according to the measured body fluid state. On the other hand, since dividing is directly controlled by the measured value, it is a big problem if the result of the measuring means is not accurate or causes an abnormality. Therefore, in such feedforward control, it is common to provide a line separate from the control line and to install a safety mechanism on the line. However, if an independent line or safety mechanism is installed, the apparatus becomes complicated and the operation is cumbersome. In addition, the cost of the device becomes high. Therefore, the simple apparatus described in Unexamined-Japanese-Patent No. 9-149935 was also devised. In other words, while monitoring the blood state of the patient, depending on the condition, an alarm sounds and the water pump is stopped. However, by comparing the blood concentration measured before the start of dialysis, the device only recognizes whether or not the dividing control is performed as a control condition at the start of dialysis, and does not perform proper dividing for each patient. If this is not done, the worker must adjust the dividing amount or the amount of remuneration each time. Therefore, although it was safe, it was cumbersome. In addition, since the apparatus is provided with a means for measuring the blood state in the venous fluid side line of the blood circuit, the blood state after passing through the blood processor (dialyzer) is measured so that the blood state of the patient may not be reflected directly. There is.

In order to provide a blood treatment device that solves the above problems, that is, it is possible to appropriately treat each patient over time while monitoring the blood state of each patient, and the burden on the worker is less when used, In order to provide an easy-to-use and inexpensive apparatus by using a simple configuration, the inventors of the present invention provide blood measurement means for measuring blood parameters, a real operation portion for performing blood treatment, and blood treatment under predetermined blood treatment conditions. A hemodialysis apparatus comprising a control unit for controlling an actual operation unit, the blood index area defined in advance for a blood index value of a patient obtained from the blood measurement means, and the change of the blood index value over time in the blood index area In response, the control unit instructs the real operation unit to change the blood processing conditions. A processing unit (Japanese Laid-Open Patent Publication No. Hei 11-22175) has been proposed. In addition, the present inventors have improved the blood processing apparatus (Japanese Patent Laid-Open No. 11-22175) to monitor the blood state of each patient, while setting the conditions of hemodialysis appropriate for each patient over time, in particular, the rate of dilution. A blood processing apparatus (Japanese Patent Laid-Open No. 2001-540) that can be easily changed and set is proposed. The blood processing apparatus (Japanese Laid-Open Patent Publication No. 2001-540) includes a blood measuring means (A) for measuring blood parameters, a real operation part (B) for performing blood processing, and blood processing under predetermined blood processing conditions. A hemodialysis apparatus comprising at least a control unit C for controlling the actual operation unit to perform the operation, wherein the control unit C measures the blood index value obtained from the sampling of the patient with the blood measurement means A, and the blood index set in advance. It is monitored whether or not it is changing within a value range (hereinafter also referred to as a set blood index range), and when the blood index value to be monitored deviates from the set range, the actual operation unit (B) Hemodialysis apparatus, characterized in that having a distillation rate control function that can change the distillation rate of the).

The hemodialysis apparatus was able to reliably manage the blood index values at each time point during the hemodialysis process, but it was cumbersome because it was necessary to set the target blood index values at each time point. In addition, since the blood indicator value to be set is designated as a range, the control mechanism of the hemodialysis apparatus does not operate even if it is within the setting range as long as there is a blood indicator value within the setting range. Therefore, there is a fear that the control may be delayed when the actually measured blood index slightly subtracts from the target. In addition, since the apparatus is finely set in each region and controlled accordingly, it is difficult to perform physiological dividing suitable for each patient. On the contrary, when the fresh water is to be gradually distilled, there may be cases where the initially set distillation amount cannot be achieved.

The present invention relates to a hemodialysis apparatus, and more particularly to a hemodialysis apparatus capable of controlling the dilution conditions and the dilution rate so as to prevent excessive dilution or vice versa, which is likely to occur during hemodialysis.

Fig. 1 is a view for explaining a control method of the whole dehydration operation of the blood processing apparatus, and Fig. 2 is a diagram showing the control of the whole dewatering operation of the blood processing apparatus. In Fig. 1, a denotes a period in which only the in vitro circulation is performed without dividing, b denotes a divisor period at the start of dividing, c, d, e, f, g, h, i, j, k, l, m, n, o and p represent the dividing speeds determined using the target control line, the alarm line E and the maximum dividing line G or H performed within a corresponding period. In Figure 2,% ΔBV _{1 '} ,% ΔBV _2' ,% ΔBV _{3 '} ,% ΔBV _4' , and% ΔBV _{5 '} are the ratios of the measured blood changes at the measurement points 1, 2, 3, 4 and 5, % ΔBV ₁ ,% ΔBV ₂ ,% ΔBV ₃ ,% ΔBV ₄ and% ΔBV ₅ are the ratios of the blood changes determined by the target control line at the measurement points 1, 2, 3, 4 and 5, and ΔT is the respective The measurement time interval between measurement points. In addition, A is the control line (first half), B is the measured value line, C is the predictive control line, D is the control line (second half), E is the deviation control line (alarm line), F is the emergency liquid line, and G is the maximum dividing speed. The line H represents the maximum dividing speed line, respectively. 3 is a view for explaining a first method of calculating the initial blood volume BV ₀ , and FIG. 4 is a view for explaining a second method for calculating an initial blood volume BV ₀ .

Best Mode for Carrying Out the Invention

1. Embodiment 1

A first calculation method of the initial blood volume BV ₀ will be described based on FIG. 3.

Since the BV value is unstable at the start of dialysis, only in vitro circulation was performed at the start of dialysis without distillation (zero dividing rate). The blood volume gradually increased, and after a certain time, the blood volume stabilized at a certain upper limit. At this point, the dialysis apparatus was reset, and the dialysis operation involving dividing was started. The initial blood volume (BV ₀₎ of each patient from n% BV value of extracorporeal blood volume increase, and the upper limit of the BV obtained by the formula (I), and also in advance, as described above with the initial blood volume (BV ₀₎ of each patient The target BV% was automatically calculated from the standard blood volume (BVst) set by a doctor or the like.

2. Embodiment 2

A second calculation method of the initial blood volume BV ₀ will be described based on FIG. 4.

In the same manner as in Embodiment 1, since the blood volume is unstable at the start of dialysis, only extracorporeal circulation was performed at the start of dialysis without distillation (zero distillation rate). The blood volume gradually increased, and after a certain time, the blood volume stabilized at a certain upper limit. The same time at this point, a predetermined time (PRR does not change hours), predetermined divisor speed performs a divisor by (divisor speed A), calculating the ratio of% ΔBV ₁ of variation values that BV and then, the predetermined period of time The dividing is carried out at different dividing speeds (dividing speed B), and% ΔBV ₂ , which is a ratio of the change amount of the BV value, is calculated, and the above-mentioned% ΔBV ₁ , the% ΔBV _2, and the dipping speed A and dipping speed B Based on Formula (II), the patient's initial blood volume (BV ₀ ) was simply found. The target BV% was automatically calculated in the same manner as in the first embodiment.

Embodiment 3

Control Mode of Dialysis Operation

The control mode of the dialysis operation in the hemodialysis apparatus of the present invention will be described based on FIG. The dividing speed set in the lower half of Fig. 1 is shown.

As shown in FIG. 1, the dividing operation is performed by setting the maximum dividing speed lines G and H in the first half and the second half of the dialysis operation, and the dividing speed (or the history) set in the first half and the second half of the dialysis operation is shown. .

Dialysis operation overall

(1) Start of dialysis

Since the BV value is unstable at the start of dialysis, at the start of dialysis, distillation is not performed (dividing speed is 0), and only the in vitro circulation is performed, and it is waited until the time interval (period a) that BV value stabilizes.

(2) Start measurement

After the BV value has stabilized, reset the hemodialysis device and resume measurement. At that time, in the dividing period b at the start of the dividing in FIG. 1, the initial blood volume (BV ₀ ) of the patient was obtained by the second embodiment. In addition, the initial blood volume BV ₀ of this patient can be obtained according to the first embodiment from the fluctuation value of the blood index value in the extracorporeal circulation and the increased extracorporeal circulating blood volume after the BV value is stabilized at the start of dialysis of the above (1). have.

In the second embodiment, control of the dividing means by the feedforward control based on the target control line is started based on the dividing speed adopted when the initial blood volume is calculated and the respective% ΔBV generated at that time. Among the dividing speeds c to i of the whole dialysis operation determined by the above control method, the dipping speeds d and h in the first half of the dialysis operation exceed the maximum dividing speed line G, and thus the maximum dividing speed is adopted. In this way, when the dividing speed exceeds the maximum dividing speed line, it is most preferable to adopt the maximum dividing speed as the dividing speed, but a dipping speed below the maximum dividing speed may be used. In addition, since the measured value of the blood amount or blood change amount at the time of dialysis of the dividing speed f was lower than the warning line, the dividing speed f = 0 (that is, not dividing).

(3) Resumption of divisor

In the whole dialysis operation, the distillation is stopped when the blood volume or the blood change level is lower than the alarm value (the dividing speed f = 0), and when the blood volume or the blood change level exceeds the control line, the distillation is restarted. Do it. The initial dividing speed of the control at the start of resumption is dividing at the dividing speed predicted by the above method. The dilution scheduled for the entire dialysis operation is to be divided to the standard blood volume, or when the blood volume percentage (% BV) reaches the target blood volume ratio (purpose% BV), the control proceeds to the dilution control at the end of the dialysis operation.

(4) Late dialysis operation

The dividing speed is calculated so that the remaining dividing amount ends at the target dividing time, and dividing is performed at this dividing speed. As a result of dividing at this dividing speed, dividing is stopped when blood amount or blood change amount becomes lower than the said alarm value. When the blood indicator value reaches the lower side beyond the emergency liquid line set below the deviation control line (alarm line), not only the actual operation means for performing blood treatment as described above is temporarily stopped, but also the liquid In combination with the liquid-retaining means for injecting, the blood indicator value was quickly recovered above the deviation control line (alarm line). For example, when distillation was performed at the distillation rate j, the blood amount or the blood change amount was lower than the alarm value. Therefore, dilution at the time of the next control was stopped, and the dividing speed k was 0.

In addition, since the actual blood change ΔBV value has recovered above the alarm value as a result of the distillation stop, the dividing speed is calculated so that the remaining distillation amount at the time of control at that time ends at the target dividing time (determined dilution amount). Divide by the decision dividing speed 1. As a result of dividing at this decision dividing speed 1, the actual ΔBV value was lower than the above alarm value. Therefore, dilution at the time of the next control was stopped and the dividing speed m was 0. In addition, since the actual ΔBV value has recovered above the control line as a result of the dividing stop, the dividing speed is calculated so that the remaining dividing amount at the time of control at that time ends in the target dividing time (determined dividing amount), and this decision dividing rate Divide by n However, since the dividing speed n of the crystal dividing speed exceeds the maximum dividing speed H, the maximum dividing speed is adopted as the actual dividing speed. Even though the target dividing time was completed, the target distillation amount was not achieved. Finally, the distillation was completed at the maximum dividing speed and the dialysis was completed.

Disclosure of the Invention

The object of the present invention,

(1) The control mechanism is simple and there is little risk of misoperation or runaway.

(2) Since complicated setting and unnecessary operation are unnecessary, it is easy for the operator to operate.

(3) An object of the present invention is to provide a hemodialysis apparatus that can achieve an effect of appropriately changing the blood volume during hemodialysis because the control is quick and precise.

The present invention provides a hemodialysis apparatus that measures or calculates the amount of blood or its amount of change as an index value (hereinafter also referred to as a blood index value), and performs a hemodialysis treatment by controlling a dialysis condition based on the blood index value. Set the course over time of the blood indicator value to be the target control line, and control the divisor to bring the circulating blood volume closer to the standard blood volume BVst using the target control line in the whole dialysis operation (hereinafter, Control of the whole dialysis operation), and when the circulating blood volume becomes the standard blood volume (BVst) by the dilution of the dialysis operation, the standard blood volume (BVst) is substantially changed in the second half of the dialysis operation. Hemodialysis site, characterized in that it controls to perform the distillation operation (hereinafter referred to as the control means of the late dialysis operation) By providing the above-described problem it could be solved.

As the blood index value, any one can be adopted as long as it indicates the amount of blood circulating in the patient. For example, BV value (Blood Volume),% BV, ΔBV derived from hematocrit value,% ΔBV and the like. The definition of these parameters and the calculation formula are described later.

Control of the dipping speed in the whole dialysis operation using the target control line is performed using the blood index value measured at each measurement point and the target blood index value indicated by the target control line at the next measurement point at each measurement point. .

In addition, the control of the dividing speed of the whole dialysis operation using the target control line includes the blood index values at two adjacent measurement points, the dividing speed carried out between the two measurement points, and the blood index values at the start of dialysis. The target blood indicator value determined by the target control line at the next measurement point after the two measurement points may be calculated.

Specifically, the control can be performed using the following formula (n).

BV ₀ {− (% ΔBV _{n−1 ′} −% ΔBV _{n ′} ) + (% ΔBV _{n ′} −% ΔBV _{n + 1} )} + UFR _n × T = UFR _{n + 1} × T... (n)

[BV ₀ is the volume of blood at the start of dialysis (also called initial blood volume),% ΔBV _{n '} is the ratio of blood change at any selected measurement point n throughout the dialysis operation, and% ΔBV _n-1' is the selected volume of dialysis operation The ratio of the blood change amount at one measurement point before measurement point _n ,% ΔBV _{n + 1} is the ratio of the blood change amount determined by the target control line at the next measurement point n + 1 at measurement point n, and T is the measurement time. UFR _n is the dividing speed at the selected measurement point throughout the dialysis operation, and UFR _{n + 1} is the control when the control is performed on the moving part to reach the target blood index value from the measurement point n to the next measurement point n + 1. Each dividing speed is set.]

The formula (n) is calculated by the following method.

If the BV value at the start of dialysis is BV ₀ (initial blood volume), the following relational expression is established between the BV values, PRR, and UFR at the first and second measurement points, for example, at each measurement point in the entire dialysis operation.

First measurement point

BV ₀ {(100%-% ΔBV ₁ )-(100%-% ΔBV ₂ )} = PRR ₁ -UFR ₁

BV ₀ (−% ΔBV _{1 ′} +% ΔBV _{2 ′} ) / T = PRR ₁ —UFR ₁ . (One)

2nd measurement point

BV ₀ (−% ΔBV _{2 ′} +% ΔBV ₃ ) / T = PRR ₂ —UFR ₂ . (2)

Here, BV ₀ ,% ΔBV _{1 ′} ,% ΔBV _{2 ′} , T denote the BV value at the start of dialysis, the ratio of the amount of BV change at the first or second measurement point, and the dialysis elapsed time, respectively. In addition,% ΔBV ₃ is determined by the target control line.

The same relationship is also established at each measurement point of arbitrary (n-1) or (n), as shown in the following relational expression.

(N-1) measurement point

BV ₀ (-% ΔBV _{n-1 ′} +% ΔBV _{n ′} ) / T = PRR _n-1 -UFR _n-1

(N) Measurement point

BV ₀ (-% ΔBV _{n '} +% ΔBV _{n + 1} ) / T = PRR _n -UFR _n

When Formula (2) is subtracted from said Formula (1), Formula (3) shown below is obtained.

BV ₀ {(% ΔBV _{1 ′} -% ΔBV _{2 ′} )-(% ΔBV _{2 ′} -% ΔBV ₃ )} / T = PRR ₁ -PRR ₂ + UFR ₂ -UFR ₁ . (3)

Here, assuming that there is no difference between PRR ₁ and PRR ₂ , i.e., if the interval between measurement points is taken short enough that a substantial change does not occur in the patient's PRR at each measurement point, the first and second terms on the right side. Clause 2 is cleared. And following formula (4) is established.

BV ₀ {− (% ΔBV _{1 ′} −% ΔBV _{2 ′} ) + (% ΔBV _{2 ′} −% ΔBV ₃ )} / T + UFR ₁ = UFR ₂ . (4)

In this equation,% ΔBV ₃ is the target value at the next measurement point, and is the value to close the blood index value by control. UFR ₂ is the dilution rate that must be set to bring the blood reading at the next measurement point closer to the target. _{Here, BV 0,% ΔBV 1 '} ,% ΔBV 2', T is a base of a BV value, the first or second measurement rate, dialysis elapsed time of the BV changing amount at the timing when each dialysis initiation, UFR ₁ also the The dividing speed from the first to the second measurement point is known. In this case, if% ΔBV ₃ which is the ratio of the target BV change amount is designated, the dividing speed which is a dialysis condition can be calculated by Formula (4). The BV target value is determined by the measurement control point by the target control line. On the contrary, when the hemodialysis treatment is performed at the dividing speed, it is possible to bring the BV value at the next measurement point closer to the target value, that is, the target control line.

When the above equation is described for any measurement point n, it is represented by the following equation (n), and as described above, the amount of BV change at the two measurement points, the dividing speed between the two measurement points, and the dialysis time T The dividing speed to be set to bring the blood indicator closer to the target at the next point of time is determined based on the set blood indicator of the next measurement point of the two measurement points determined based on the measured value of the blood point and the target control line of the blood index point. .

BV ₀ {− (% ΔBV _{n−1 ′} −% ΔBV _{n ′} ) + (% ΔBV _{n ′} −% ΔBV _{n + 1} )} / T + UFR _n = UFR _{n + 1} . (n)

In the above formula, BV ₀ is the blood volume at the start of dialysis,% ΔBV _{n '} is the ratio of blood change at any selected measurement point n throughout the dialysis operation, and% ΔBV _{n-1 ′} is any selected measurement point throughout the dialysis operation. The ratio of the blood change at the measurement point one previous to n,% ΔBV _{n + 1} is the ratio of the set blood change at the measurement point (the next measurement point of measurement point n) throughout the dialysis operation to which feedforward control is to be applied, T Is the measurement time, UFR _n is the dividing speed at the selected measurement point throughout the dialysis operation, and UFR _{n + 1} is the selected motion point from the selected n measurement point throughout the dialysis operation to the next measurement point, in order to reach the target blood index. Each of the dividing speeds set when the control is applied to the negative means. However, in order for the above equations (4) and (n) to be established, the condition is that "there is no difference in PRR at each measurement point" assumed to derive these equations, and in order to satisfy the condition It is important to shorten the interval ΔT between the respective measurement points so that there is no difference. In addition, in this control method, an error may occur in the control due to the error of BV ₀ , the control delay, and other factors at the start of dialysis, but in actual control, the control is assured by resetting the dividing speed at each time point (measurement time point). I'm letting you.

That is, in the dividing operation of the whole dialysis operation, as described above, the interval between the respective measurement points is shortened and the dividing speed is set at each time, so that the generated error is not substantially a problem.

The distillation is performed while the dividing speed is controlled by the control means as described above, and the flow shifts to the dialysis operation in the latter half of the dialysis operation when the circulating blood volume approaches the standard blood volume. At the time of shifting to the dialysis operation in the second half of the dialysis operation, the remaining dilution amount of the target dilution amount is measured or calculated, and the dividing speed is recalculated so that the dividing amount is finished at the target dividing time, and the You can carry out the second half of the dialysis operation.

In the distillation operation of the hemodialysis apparatus of the present invention, the maximum distillation rate is set in advance separately in the first half of the dialysis operation and the second half of the dialysis operation, and when the distillation speed calculated in the first half or the second dialysis operation exceeds the maximum distillation speed, It is preferable to control so as to divide at the maximum dividing speed.

In the hemodialysis operation of the hemodialysis apparatus of the present invention, a deviation control line (alarm line) for limiting the change over time of the blood indicator value to the lower side of the target control line to a predetermined range is separated separately in the first half and the second half of the dialysis operation. When the blood index value exceeds the deviation control line (alarm line), the actual operation of performing hemodialysis treatment is performed so that the dialysis condition for restoring the blood index value above the deviation control line (alarm line) is executed. It is preferable to control by means.

As means for restoring the blood indicator value above the deviation control line (alarm line), there is a means for temporarily stopping the dividing means.

In the first half of the dialysis operation, as a result of performing the means for recovering the blood index value above the deviation control line (alarm line), when the blood index value is restored above the deviation control line (alarm line), the overall control of the dialysis operation is performed. Resume dialysis operation according to the above. Further, in the second half of the dialysis operation, as a result of performing the means for recovering the blood index value above the deviation control line (alarm line), at the time when the blood index value has recovered above the deviation control line (alarm line), The dividing speed is recalculated so that the remaining distillation amount at the target dividing time ends, and the dialysis operation in the second half of the dialysis operation is resumed at the dividing speed.

In addition, the control of the water removal operation in the hemodialysis apparatus of the present invention, especially in the latter part of the dialysis operation, is set below the deviation control line (alarm line), and the blood index value goes further and reaches the lower side beyond the emergency maintenance line. In this case, not only the actual operation means for performing blood treatment as described above is temporarily stopped, but also the liquid holding means for injecting the liquid into the body is used, and the blood index value is rapidly exceeded the deviation control line (alarm line). It is desirable to be controllable to recover.

In addition, the inventors of the present invention may show that a change in blood volume may be delayed in response to a change in the distillation speed in the control of the distillation speed using the target control line (especially when the target control line changes abruptly). In addition, in the case where the feedforward control is carried out while ignoring such a phenomenon, it has been found that a problem arises that the control is not stable, and in order to solve this problem, the control delay is generated by considering the control delay. It is proposed to solve the problem (Japanese Patent Application 2002-19447), which is necessary to reach the blood index value (blood change) of the next target in the method of the proposal, for example, the method of controlling the dipping speed using the target control line. Means for calculating the prediction of the dialysis condition based on the blood indicator value at the time when the control delay time has elapsed are In the control method of dividing speed using the said target control line of this invention, when the problem of the control delay mentioned above arises, you may adopt.

Hereinafter, the blood index values and parameters related to blood used in the hemodialysis apparatus of the present invention will be described in detail.

Initial blood volume (BV ₀ )

As one of the control elements throughout the dialysis operation, it is desirable to use the patient's own initial blood volume. This patient-specific initial blood volume can be calculated, for example, by the following two methods.

(1) First calculation method of initial blood volume BV ₀

A first calculation method of the initial blood volume BV ₀ will be described based on FIG. 3.

When dialysis is started, blood volume is unstable, so extracorporeal circulation is performed without dilution. Continued extracorporeal circulation until blood volume stabilizes. It is thought that the body fluid (inflow amount from the cells shown in Fig. 3) corresponding to the circulating blood volume (extra space) moves from the cells to the blood vessels. Thus, the amount of blood from a CPB (cardiopulmonary space) and% ΔBV _X increased when, on the basis of the following formula (I) it is possible to find the initial blood volume (BV ₀₎ of each patient.

Initial blood volume (BV ₀ ) = increased extracorporeal blood volume (extra space) /% ΔBV _X. (I)

(% ΔBV _X is the ratio of blood change when extracorporeal circulation is performed without dividing)

(2) Second calculation method of initial blood volume BV ₀

The initial blood volume (BV ₀ ) of each patient can also be obtained by the following method. This second calculation method will be described based on FIG. 4.

Using the hemodialysis apparatus that controls the dialysis conditions based on the blood index value, as shown in FIG. 4, the in vitro circulation was performed without performing dehydration at the start of dialysis and until the blood volume (BV) value was stabilized. Subsequently, when the blood volume (BV) value is stabilized, dialysis with diarrhea is started, and at the same time as the start of dialysis, dividing is performed at a constant time ΔT (within the time when the PRR does not change) and at a constant dilution rate (dividing speed A). one calculates a change amount of ΔBV _a value, and then, subjected to a divisor with a different divisor speed (divisor speed B) by the same time with the predetermined time ΔT and calculating the change amount of ΔBV _B values that BV, the ΔBV _a and the ΔBV _B and the divisor It can be calculated using the speed A and the dividing speed B.

Calculating the initial blood volume (BV ₀₎ of each patient according to the second method, specifically, it can be calculated on the basis of the following formula (II).

BV ₀ = (dividing speed A-dividing speed B) / (-ΔBV _A % + ΔBV _B %) × ΔT... (II)

The formula can be calculated by the following method. The calculation method is demonstrated based on FIG.

ΔBV / ΔT = PRR-UFR

-ΔBV _A / ΔT + ΔBV _B / ΔT = Dividing Speed A-Dividing Speed B

ΔBV _A = BV ₀ ㆍ% ΔBV _A

ΔBV _B = BV ₀ ㆍ% ΔBV _B

BV ₀ / ΔT (-% ΔBV _A +% ΔBV _B ) = Dividing Speed A-Dividing Speed B

BV ₀ / ΔT = (Division _A -Division B) / (-% ΔBV _A +% ΔBV _B )

The hemodialysis apparatus of the present invention automatically calculates a target BV% based on the following equation from the initial blood volume BV ₀ of each patient and the standard blood volume BVst set by a doctor or the like calculated in the same manner as above. It is preferable that it is the structure which enabled control by the blood index value by this.

Target BV% = standard blood volume (BVst) / initial blood volume (BV ₀ ) * 100

In addition, the standard blood volume BVst considers factors influencing the blood volume of the human body, for example, the age, sex, height, etc. of the patient, and in advance, the doctor may determine the blood volume BVst determined to have if the patient is a healthy healthy person. This is the determined value.

The method for calculating the initial blood volume BV ₀ of the present invention is not limited to the hemodialysis apparatus that controls the distillation operation by dividing the dialysis operation into the first half and the second half, as shown in the calculation method. It can be widely adopted as long as it is a hemodialysis apparatus that measures or calculates the hemodialysis and controls hemodialysis treatment based on the hemoglobin value.

2. Definition and formula of blood indicators, blood volume or changes in blood

(1) BV Chi

BV value is an abbreviation of Blood Volume value and means the circulating blood volume index which is an indicator for checking the state of the circulating blood volume of each patient.

(2) ΔBV value

Means the amount of BV change, it is calculated based on the following equation.

ΔBV [BV variation] = (Ht at dialysis start / Ht at measurement) -1

Ht is an abbreviation of hematocrit which indicates the volume ratio of red blood cells in whole blood.

(3)% ΔBV

The ratio of the amount of BV change is shown, and as shown in the following formula, the ΔBV value at the time of measurement is divided by BV ₀ at the start of dialysis and expressed as a percentage.

ΔBV% = ΔBV / BV ₀ × 100

(4) BV%

The BV value at the time of measurement is divided by BV ₀ at the start of dialysis and expressed as a percentage.

BV% = BV value at the time of measurement / BV ₀ X 100

3. Definition and calculation of parameters for other blood

(1) Definition of PRR

PRR is an abbreviation of Plasma Refilling Rate, defined as the rate at which plasma is replenished from the body to blood vessels, and represents the ability of the patient at each time point.

(2) Formula of PRR

PRR is computed by the following formula.

PRR _n -UFR _n = ΔBV _n / T _n

[PRR _n is the Plasma Refilling Rate at any selected measurement point n, UFR _n is the distillation rate at any selected measurement point n, ΔBV _n is the amount of blood change at any selected measurement point n, and T _n is any selected Elapsed time to measurement point n, UFR means dividing speed.]

Hereinafter, the target control line, the measured value line, and the predictive control line used in the hemodialysis apparatus of the present invention will be described.

2 represents the% ΔBV value, and the horizontal axis represents the elapsed time from the start of dialysis.

1. Target control line

In FIG. 1, it is shown by the inclination line A in the first half of dialysis, and is shown by the horizontal line D in the latter part of dialysis. According to the target control line of FIG. 1, the dialysis operation is performed in the first half of the dialysis operation without detriment to the living body. For example, in the second half of the dialysis operation, the blood volume is maintained for each patient according to the target control line. Dialysis, for example distillation, is carried out so as to keep the constant. Therefore, this target control line serves as a reference for the course of the blood index values over time or the target values over time. The target control line is set by the doctor or the like before dialysis, and the inclination angle is determined in relation to the target dilution amount.

2. Actual value line and predictive control line

It demonstrates based on FIG. 1 and 2. FIG. The measured value line B is the ratio of the blood change amount which consists of actual measured values of blood indicator values, such as% (DELTA) BV _{1 '} and% (DELTA) BV _2' . The predictive control line next to the target control line A is determined by the blood indicator value based on measured values such as BV, ΔBV or% ΔBV at the measurement point (control point) and the target control line A at the next measurement point (control point). Dialysis conditions (e.g., distillation rate) for reaching the target hemoglobin value at the next measurement time (control point) are calculated from the target blood index values indicated, and the next measurement time point is calculated based on the calculated dialysis conditions (e.g., distillation rate). As a result of performing the hemodialysis treatment to reach the control point, the measured value line B, which is easy to deviate from the target control line A, is corrected by the newly set dialysis conditions at each measurement point (control point), and the target control line A is changed. The predicted control line C changes accordingly.

3. Deviation control line (alarm line) and emergency maintenance line

In the first half of the dialysis operation, the inclination line of which the right side descends below the target control line and the horizontal line in the second half of the dialysis operation are deviation control lines E (alarm lines) E for functioning as a deviation control line (alarm line). In the second half of the dialysis operation, the emergency maintenance line F is set to the horizontal line below the deviation control line E (alarm line) E. FIG.

In the case where the dialysis operation is performed by the control of the hemodialysis apparatus of the present invention, when the blood indicator value measured in the first half and the second half of the dialysis operation exceeds the deviation control line E, the emergency control is adopted. Preferably, for example, it is preferable to adopt emergency control different from the feedforward control method using the target control line in the whole dialysis operation. For example, as shown in the graph of FIG. 1, when the measured value line indicating the change of the measured value deviates to the lower side of the alarm line E, the stop of the dividing means such as a water pump or the measured value line before the control by the feedforward is performed. When it deviates to the lower side of this urgent fluid line F, the liquid holding | maintenance with respect to a patient by a liquid pump is performed preferentially as needed.

As described above, the hemodialysis apparatus of the present embodiment not only functions to approximate the blood index value to the target, but also ensures the safety of the patient by preferentially operating the emergency control when the (blood index value) deviates from the dangerous area. can do. In addition, the set dividing speed is shown in the lower half of the graph of FIG.

The hemodialysis apparatus of the present embodiment is also used in the second half of the dialysis operation as described above to stop the distillation means such as a distillation pump or to maintain the replenishment pump, if necessary, by using the deviation control line E or the emergency maintenance line F. Rejuvenation for patients by Therefore, the hemodialysis apparatus of the present embodiment not only has a function of simply bringing the hemodialysis blood indicator value closer to the target or the standard blood volume in the entire dialysis operation, but also in the first half of the dialysis operation and / or in the late dialysis operation. In the case of a deviation from the dangerous area, the safety of the patient can also be ensured by preferentially operating emergency control.

The second half of the dialysis operation shifts to the distillation control in the second half of the dialysis operation when the dilution amount scheduled for the entire dialysis operation is divested. At the point of this transition, the dividing speed is calculated and dividing is carried out at this dividing speed so that the remaining dividing water ends at the target dividing time. When the dividing speed exceeds the maximum dividing speed line set in the second half of the dialysis operation, Hemodialysis is performed at the maximum dilution rate as in the general dialysis operation.

By the hemodialysis apparatus of this invention, the outstanding effect shown below (1)-(3) was obtained.

(1) The control mechanism is simple and there is little risk of misoperation or runaway.

(2) Since complicated setting and unnecessary operation are unnecessary, it is easy for the operator to operate.

(3) Since the control is quick and precise, the blood volume can be properly changed during hemodialysis.

Claims (13)

A hemodialysis apparatus that measures or calculates the amount of blood or its amount of change as a blood index value and controls the dialysis condition based on the blood index value to perform hemodialysis treatment, wherein the target control over time of the blood index value to be targeted is controlled. In the first half of the dialysis operation, using the target control line, dividing the circulating blood volume to the standard blood volume BVst is controlled. At the time point of BVst), the process shifts to the second dialysis operation, and the second dialysis operation is controlled to perform the distillation operation while substantially maintaining the standard blood volume BVst. A hemodialysis apparatus that measures or calculates the amount of blood or the amount of change thereof as a blood index value and controls the dialysis conditions based on the blood index value to perform hemodialysis treatment. Set to a line, do not dividing at the start of dialysis, only the extracorporeal circulation is continued, and the extracorporeal circulation is continued until the blood volume stabilizes, and the initial blood volume of each patient from the fluctuation value of the blood index value and the increased extracorporeal blood volume ( Hereinafter, also referred to as BV ₀ ) hemodialysis apparatus, characterized in that configured to be configured. The hemodialysis apparatus according to claim 2, wherein the initial blood volume BV ₀ is calculated based on the following formula (I). Initial blood volume (BV ₀ ) = increased extracorporeal circulating blood volume (extra space) /% ΔBV _x ... (I) (% ΔBV _x is the ratio of blood change when extracorporeal circulation is performed without dividing) The method of claim 2, wherein in vitro circulation is carried out without distillation at the start of dialysis, and the in vitro circulation is continued until the blood volume is stabilized, and dialysis with distillation is started within a predetermined time when the blood volume level is stabilized. (During the time when the PRR does not change), distillation is carried out at a constant distillation rate (distillation rate A) to calculate% ΔBV ₁ , which is the ratio of the amount of blood change, and then a different distillation rate (distillation rate) within the same time as the predetermined time. B) dividing, calculating% ΔBV ₂ , which is the ratio of the amount of blood change, and using the% ΔBV ₁ , the% ΔBV _2, and the dilution rate A and the dilution rate B, the initial blood volume (BV ₀₎ of each patient. Hemodialysis apparatus, characterized in that configured to be calculated. The hemodialysis apparatus according to claim 4, wherein the initial blood volume (BV ₀ ) of each patient is calculated based on the following formula (II). BV ₀ = (dividing speed A-dividing speed B) / (-% ΔBV _A +% ΔBV _B ) × ΔT... (II) [% ΔBV _A is% ΔBV which occurs when dividing at dividing speed A,% ΔBV _B is% ΔBV which occurs when dividing at dividing speed B, and ΔT means constant time without changing PRR.] The hemodialysis apparatus according to claim 1, wherein the transition to the second half of the dialysis operation is the timing at which% BV becomes the target% BV or% ΔBV. 7. The target blood according to claim 1 or 6, wherein the control of the dividing speed using the target control line in the first half of dialysis is indicated by the blood indicator value measured at each measurement point and the target control line at the next measurement point at each measurement point. A hemodialysis apparatus, characterized in that for controlling the dilution rate using the indicator value. 8. The dialysis rate control according to claim 1, 6 or 7, wherein the control of the distillation rate using the target control line for dialysis is performed by each blood indicator value at two adjacent measurement points, the distillation rate performed between the two measurement points, and the dialysis start point. A dividing speed for reaching the target blood indicator value at the next measurement point is calculated using the blood index value at the time point and the target blood indicator value determined by the target control line at the next measurement point of the two measurement points. Hemodialysis apparatus. 9. The hemodialysis apparatus according to claim 8, wherein the control of the dilution speed is performed using the following formula (n). BV ₀ {− (% ΔBV _{n−1 ′} −% ΔBV _{n ′} ) + (% ΔBV _{n ′} −% ΔBV _{n + 1} )} / T + UFR _n = UFR _{n + 1} . (n) (BV ₀ is the blood volume at the start of dialysis,% ΔBV _{n '} is the proportion of blood change at any selected measurement point n throughout the dialysis operation, and% ΔBV _{n-1 ′} is one of the selected measurement points n during the dialysis operation. The ratio of the blood change amount at the measurement point,% ΔBV _{n + 1} is the ratio of the blood change amount determined by the target control line at the next measurement point n + 1 at the measurement point n, T is the measurement time, and UFR _n is the dialysis operation. The dividing speed at the selected measuring point in the first half, UFR _{n + 1,} is the dividing speed set when applying control to the real moving part to reach the target blood index value from the measuring point n to the next measuring point n + 1. Each mean, and the interval of each measurement point is set so short that there is no substantial difference in the patient's PRR at each time point) 10. The dividing speed according to claim 1, 6, 7, 8, or 9, in the second half of the dialysis operation, is calculated by recalculating the dividing speed so that the remaining distillation amount ends at the target dividing time at the time of shifting to the second dialysis operation. Hemodialysis apparatus, characterized in that. The maximum dividing speed is set in advance separately in the first half of the dialysis operation and the second half of the dialysis operation, and when the dividing speed exceeds the maximum dividing speed, the set maximum A hemodialysis apparatus, wherein the dialysis is performed at a dicing speed. 12. The first half of the dialysis operation according to claim 1, 6, 7, 8, 9, 10, or 11, wherein a deviation control line (alarm line) is provided below the target control line for limiting the change over time of the blood indicator value to a predetermined range. And separately set in the latter half, and in the case where the blood index value exceeds the deviation control line (alarm line), the blood index value has control means for dividing operation to recover above the deviation control line (alarm line). Hemodialysis apparatus characterized in that. The emergency maintenance line according to claim 1, 6, 7, 8, 9, 10, 11, or 12 is set below the deviation control line (alarm line) in the second half of the dialysis operation, and the blood index value is set to the deviation control line ( When exceeding the warning line, and the lower side is reached, the water-removal operation is temporarily stopped, and a liquid retaining means for injecting the liquid into the body is used to recover the blood indicator value above the deviation control line (alarm line). Hemodialysis apparatus, characterized in that for controlling the actual operation means.